A new and improved control of a power electronic converter for stabilizing a variable speed generation system using an embedded microcontroller

• Main Author: Venkatswamy, Suresh
• Other Authors: Rathja, Roy C.
• Language: en_US
• Published: 2013
• Subjects: Variable speed drives; Electric controllers; Embedded computer systems
• Online Access: http://hdl.handle.net/1957/37634

A new and improved stabilizer was developed for the variable speed generation (VSG) system. The VSG system exhibits periodic oscillations which sometimes leads to a loss of synchronism. After careful study, a simple but effective strategy to stabilize the system was implemented with real time digital feedback control. The VSG system consists of an engine, which is the prime mover, driving a doubly fed machine (DFM), which is the generator. The stator of the DFM is directly connected to the grid while the rotor is connected to the grid through a power electronic converter. The converter used in this study is a series resonance converter (SRC), but the proposed method may also be applied to other kinds of converters. The stabilizer senses the RPM of the engine, the feedback signal, and controls the rotor current amplitude and frequency of the doubly fed machine. Control was implemented using the 80C196KB microcontroller. The software consists of a mix of "C" and assembly language. Speed being an important factor in the implementation, care was taken to minimize the control loop times. The important features of the hardware and software developed for the stabilizer are: (1) 12 MHz controller board (2) Real time digital band pass filter (3) Instantaneous rotor speed measurement (4) Interrupt driven measurement and control loops (5) User defined setup parameters (6) IBM PC based real time serial communication The performance of the VSG system was studied with and without the stabilizer. A significant improvement in the stability of the system was noticed over the entire region of operation. === Graduation date: 1991